let str:string="123"

console.log(str);

let num:number=456

console.log(num);


let br:boolean=true

console.log(br);

let  arr:number[]=[1,2,4]

console.log( arr);


let obj={
    name:'zhangsan',
    age:18
}
console.log(obj);

let arr1:string[]=["12","1907c"];//推荐这种






